Overall, The way reservations work in D365 BC is way more complicated that it needs to be. There really is no need for reservations to be linked to the individual item ledger transactions that make up the sum of the inventory that is on hand, as all the items of a particular item and lot number combination should be identical to each other. It really does not matter which particular bin the stock gets picked from, because it's all the same. A simple reservation ledger that adds and subtracts reservations, tagged to particular item numbers and lots is all that is needed, with the system simply summing up the entries to determine whether there is, or isn't any available (unreserved) stock. The sheer unnecessary complexity of how reservations work has caused huge headaches for our vendor partner, and considerable development expense for my organization.